Pressure as a physical quantity. Blood pressure: what is considered normal, how to measure it, what to do if it is high and low? Video: blood pressure in the program “Live Healthy!”

Imagine a sealed cylinder filled with air, with a piston installed on top. If you start to press on the piston, the volume of air in the cylinder will begin to decrease, air molecules will begin to collide with each other and with the piston more and more intensely, and the pressure of compressed air on the piston will increase.

If the piston is now sharply released, the compressed air will sharply push it upward. This will happen because, with a constant area of the piston, the force acting on the piston from the compressed air will increase. The area of the piston remained unchanged, but the force exerted by the gas molecules increased, and the pressure increased accordingly.

Or another example. A man stands on the ground, stands with both feet. In this position, a person is comfortable and does not experience any discomfort. But what happens if this person decides to stand on one leg? He will bend one of his legs at the knee, and will now rest on the ground with only one foot. In this position, a person will feel a certain discomfort, because the pressure on the foot has increased, approximately 2 times. Why? Because the area through which gravity now presses a person to the ground has decreased by 2 times. Here is an example of what pressure is and how easily it can be detected in everyday life.

From the point of view of physics, pressure is a physical quantity that is numerically equal to the force acting perpendicular to a surface per unit area of a given surface. Therefore, to determine the pressure at a certain point on the surface, the normal component of the force applied to the surface is divided by the area of the small element of the surface, which given power works. And in order to determine the average pressure over the entire area, the normal component of the force acting on the surface must be divided by the total area of this surface.

Pressure is measured in pascals (Pa). This unit of measurement of pressure got its name in honor of the French mathematician, physicist and writer Blaise Pascal, the author of the fundamental law of hydrostatics - Pascal's Law, which states that the pressure exerted on a liquid or gas is transmitted to any point without changes in all directions. The pressure unit "pascal" was first introduced into circulation in France in 1961, according to the decree on units, three centuries after the death of the scientist.

One pascal is equal to the pressure caused by a force of one newton, uniformly distributed, and directed perpendicular to a surface of one square meter.

Pascals measure not only mechanical pressure(mechanical stress), but also modulus of elasticity, Young's modulus, bulk modulus of elasticity, yield strength, proportional limit, tensile strength, shear strength, sound pressure and osmotic pressure. Traditionally, it is in pascals that the most important mechanical characteristics of materials in strength materials are expressed.

Atmosphere technical (at), physical (atm), kilogram-force per square centimeter(kgf/cm2)

In addition to pascal, other (non-system) units are also used to measure pressure. One such unit is the “atmosphere” (at). The pressure of one atmosphere is approximately equal to the atmospheric pressure on the surface of the Earth at ocean level. Today, “atmosphere” refers to the technical atmosphere (at).

Technical atmosphere (at) is the pressure produced by one kilogram-force (kgf) distributed evenly over an area of one square centimeter. And one kilogram-force, in turn, is equal to the force of gravity acting on a body weighing one kilogram under conditions of gravitational acceleration equal to 9.80665 m/s2. One kilogram-force is thus equal to 9.80665 newtons, and 1 atmosphere turns out to be equal to exactly 98066.5 Pa. 1 at = 98066.5 Pa.

In atmospheres, for example, pressure is measured in car tires, for example, the recommended tire pressure for the GAZ-2217 passenger bus is 3 atmospheres.

There is also a “physical atmosphere” (atm), defined as the pressure of a column of mercury, 760 mm high, at its base, given that the density of mercury is 13595.04 kg/m3, at a temperature of 0 ° C and under conditions of gravity acceleration equal to 9, 80665 m/s2. So it turns out that 1 atm = 1.033233 atm = 101,325 Pa.

As for kilogram-force per square centimeter (kgf/cm2), this extra-systemic unit of pressure is equal to normal atmospheric pressure with good accuracy, which is sometimes convenient for assessing various effects.

The off-system unit "bar" is approximately equal to one atmosphere, but is more accurate - exactly 100,000 Pa. In the CGS system, 1 bar is equal to 1,000,000 dynes/cm2. Previously, the name “bar” was given to a unit now called “barium” and equal to 0.1 Pa or in the CGS system 1 barium = 1 dyne/cm2. The word "bar", "barium" and "barometer" all come from the same Greek word for "gravity".

The unit mbar (millibar), equal to 0.001 bar, is often used to measure atmospheric pressure in meteorology. And to measure pressure on planets where the atmosphere is very rarefied - μbar (microbar), equal to 0.000001 bar. On technical pressure gauges, most often the scale is graduated in bars.

Millimeter of mercury (mmHg), millimeter of water (mmHg)

The non-system unit of measurement “millimeter of mercury” is equal to 101325/760 = 133.3223684 Pa. It is designated “mmHg”, but is sometimes denoted “torr” - in honor of the Italian physicist, Galileo’s student, Evangelista Torricelli, the author of the concept of atmospheric pressure.

The unit was formed due to in a convenient way measuring atmospheric pressure with a barometer, in which the mercury column is in equilibrium under the influence of atmospheric pressure. Mercury has high density about 13600 kg/m3 and is characterized by low saturated vapor pressure at room temperature, which is why mercury was chosen for barometers at one time.

At sea level Atmosphere pressure is equal to approximately 760 mm Hg, it is this value that is now considered normal atmospheric pressure, equal to 101325 Pa or one physical atmosphere, 1 atm. That is, 1 millimeter of mercury is equal to 101325/760 pascal.

Pressure is measured in millimeters of mercury in medicine, meteorology, and aviation navigation. In medicine, blood pressure is measured in mmHg, in vacuum technology it is graduated in mmHg, along with bars. Sometimes they even simply write 25 microns, meaning microns of mercury, if we're talking about about evacuation, and pressure measurements are carried out with vacuum gauges.

In some cases, millimeters of water column are used, and then 13.59 mm water column = 1 mm Hg. Sometimes this is more appropriate and convenient. A millimeter of water column, like a millimeter of mercury, is a non-systemic unit, equal in turn to the hydrostatic pressure of 1 mm of a water column, which this column exerts on a flat base at a water column temperature of 4 ° C.

Why doesn't a person standing on skis fall into the loose snow? Why does a car with wide tires have better cross-country capability than a car with regular tires? Why does a tractor need tracks? We will learn the answer to these questions by becoming familiar with the physical quantity called pressure.

Solid pressure

When a force is applied not to one point of the body, but to many points, then it acts on the surface of the body. In this case, we talk about the pressure that this force creates on the surface of a solid body.

In physics, pressure is a physical quantity that is numerically equal to the ratio of the force acting on a surface perpendicular to it to the area of this surface.

p = F/S ,

Where R - pressure; F - force acting on the surface; S - surface area.

So, pressure occurs when a force acts on a surface perpendicular to it. The amount of pressure depends on the magnitude of this force and is directly proportional to it. The greater the strength, the more pressure it creates per unit area. An elephant is heavier than a tiger, so it exerts more pressure on the surface. A car presses on the road with more force than a pedestrian.

The pressure of a solid is inversely proportional to the surface area on which the force acts.

Everyone knows that walking in deep snow is difficult because your feet constantly sink. But it's quite easy to do it on skis. The thing is that in both cases a person acts on the snow with the same force - gravity. But this force is distributed over surfaces with different areas. Since the surface area of the skis more area shoe soles, then the person’s weight in this case is distributed over a larger area. And the force acting per unit area turns out to be several times smaller. Therefore, a person standing on skis puts less force on the snow and does not fall into it.

By changing the surface area, you can increase or decrease the amount of pressure.

When going on a hike, we choose a backpack with wide straps to reduce pressure on the shoulder.

To reduce the pressure of the building on the ground, the area of the foundation is increased.

Tires trucks They are made wider than passenger car tires so that they exert less pressure on the ground. For the same reason, a tractor or tank is made on caterpillar tracks, and not on wheels.

Knives, blades, scissors, and needles are sharpened so that they have the smallest possible cutting or piercing area. And then, even with the help of a small applied force, a lot of pressure is created.

For the same reason, nature provided animals sharp teeth, fangs, claws.

Pressure is a scalar quantity. In solids it is transmitted in the direction of the force.

The unit of force is newton. The unit of area measurement is m2. Therefore, the unit of measurement for pressure is N/m2. This quantity in the international system of SI units is called pascal (Pa or Ra). It got its name in honor of the French physicist Blaise Pascal. A pressure of 1 pascal is caused by a force of 1 newton acting on a surface measuring 1 m2.

1 Pa = 1 N/m2 .

Other systems use units such as bar, atmosphere, mmHg. Art. (millimeters of mercury), etc.

Pressure in liquids

If in solid body pressure is transmitted in the direction of the force, then in liquids and gases, according to Pascal’s law, “ any pressure exerted on a liquid or gas is transmitted in all directions without change ».

Let's fill a ball with tiny holes connected to a narrow tube in the form of a cylinder with liquid. Let's fill the ball with liquid, insert a piston into the tube and start moving it. The piston presses on the surface of the liquid. This pressure is transmitted to every point in the fluid. Liquid begins to pour out of the holes in the ball.

Filling the ball with smoke, we will see the same result. This means that in gases pressure is also transmitted in all directions.

A liquid, like any body on the surface of the Earth, is affected by gravity. Each layer of liquid in the container creates pressure with its weight.

This is confirmed by the following experience.

If you pour water into a glass vessel with a rubber film instead of a bottom, the film will bend under the weight of the water. And the more water there is, the more the film will bend. If we gradually immerse this vessel with water in another container, also filled with water, then as it descends the film will straighten. And when the water levels in the vessel and the container are equal, the film will straighten out completely.

At one level, the pressure in the liquid is the same. But with increasing depth it increases, since molecules upper layers exert pressure on the molecules of the lower layers. And they, in turn, put pressure on the molecules of the layers located even lower. Therefore, at the lowest point of the container the pressure will be highest.

Pressure at depth is determined by the formula:

p = ρ g h ,

Where p - pressure (Pa);

ρ - liquid density (kg/m3);

g - free fall acceleration (9.81 m/s);

h - height of the liquid column (m).

From the formula it is clear that pressure increases with increasing depth. The lower a submersible goes in the ocean, the more pressure it will experience.

Atmosphere pressure

Evangelista Torricelli

Who knows, if in 1638 the Duke of Tuscany had not decided to decorate the gardens of Florence with beautiful fountains, atmospheric pressure would not have been discovered in the 17th century, but much later. We can say that this discovery was made by accident.

In those days, it was believed that water would rise behind the pump piston because, as Aristotle stated, “nature abhors a vacuum.” However, the event was not a success. The water in the fountains actually rose, filling the resulting “void,” but it stopped at a height of 10.3 m.

They turned to Galileo Galilei for help. Since he could not find a logical explanation, he instructed his students - Evangelista Torricelli And Vincenzo Viviani conduct experiments.

Trying to find the reason for the failure, Galileo's students found out that different liquids rise behind the pump to different heights. The denser the liquid, the lower the height it can rise. Since the density of mercury is 13 times greater than the density of water, it can rise to a height 13 times less. That's why they used mercury in their experiment.

In 1644 the experiment was carried out. A glass tube was filled with mercury. Then it was tipped into a container also filled with mercury. After some time, the column of mercury in the tube rose. But he didn't fill the whole tube. There was empty space above the column of mercury. It was later called the “Torricellian void.” But mercury did not pour out of the tube into the container either. Torricelli explained this by the fact that there is pressure on mercury atmospheric air and holds it in the tube. And the height of the mercury column in the tube shows the magnitude of this pressure. This was the first time atmospheric pressure was measured.

The Earth's atmosphere is its shell of air held near it by gravitational attraction. The molecules of the gases that make up this shell move continuously and chaotically. Under the influence of gravity, the upper layers of the atmosphere press on the lower layers, compressing them. The lowest layer, located at the surface of the Earth, is the most compressed. Therefore, the pressure there is the greatest. According to Pascal's law, it transmits this pressure in all directions. It is experienced by everything that is on the surface of the Earth. This pressure is called atmospheric pressure .

Since atmospheric pressure is created by the overlying layers of air, it decreases with increasing altitude. It is known that high in the mountains it is less than at the foot of the mountains. And deep underground it is much higher than on the surface.

Normal atmospheric pressure is considered to be a pressure equal to the pressure of a column of mercury 760 mm high at a temperature of 0 o C.

Atmospheric pressure measurement

Since atmospheric air has different densities at different altitudes, the value of atmospheric pressure cannot be determined using the formulap = ρ · g · h . Therefore, it is determined using special devices called barometers .

There are liquid barometers and aneroids (liquid-free). The operation of liquid barometers is based on changes in the liquid level under atmospheric pressure.

An aneroid is a sealed container made of corrugated metal, inside of which a vacuum is created. The container contracts when atmospheric pressure increases and expands when it decreases. All these changes are transmitted to the pointer using a springy metal plate. The end of the arrow moves along the scale.

By changing the barometer readings, you can predict how the weather will change in the coming days. If the atmospheric pressure rises, then clear weather can be expected. And if it goes down, it will be cloudy.

We all had our blood pressure taken. Almost everyone knows that normal indicator pressure is 120/80 mmHg. But not everyone can answer what these numbers actually mean.

Let’s try to figure out what upper/lower pressure actually means, and how these values differ from each other. First, let's define the concepts.

Blood pressure (BP) is one of the most important indicators, it demonstrates the functioning of the circulatory system. This indicator is formed with the participation of the heart, blood vessels and blood moving through them.

Blood pressure is the pressure of blood on the artery wall

Moreover, it depends on the resistance of the blood, its volume “ejected” as a result of one contraction (this is called systole), and the intensity of heart contractions. Most high rate Blood pressure can be observed when the heart contracts and “throws” blood out of the left ventricle, and is lowest when it enters the left ventricle. right atrium when the main muscle is relaxed (diastole). Now we come to the most important thing.

By upper pressure or, in scientific terms, systolic, we mean the pressure of the blood during contraction. This indicator shows how the heart contracts. The formation of such pressure is carried out with the participation of large arteries (for example, the aorta), and depends this indicator on a number of key factors.

These include:

left ventricular stroke volume;
aortic distensibility;
maximum release speed.

As for the lower pressure (in other words, diastolic), it shows how much resistance the blood experiences as it moves through the blood vessels. Low pressure occurs when the aortic valve closes and blood cannot return to the heart. At the same time, the heart itself is filled with other blood, saturated with oxygen, and prepares for the next contraction. The movement of blood occurs as if by gravity, passively.

Factors affecting diastolic pressure include:

heart rate;
peripheral vascular resistance.

Note! IN in good condition the difference between the two indicators ranges between 30 mm and 40 mm Hg, although much depends on the person’s well-being. Despite the fact that there are specific figures and facts, each organism is individual, as well as its arterial pressure.

We conclude: in the example given at the beginning of the article (120/80), 120 is the indicator of the upper blood pressure, and 80 is the lower one.

Blood pressure - norm and deviations

Typically, the formation of blood pressure depends mainly on lifestyle, nutritious diet, habits (including harmful ones), frequency of stress. For example, by eating this or that food you can specifically lower/increase your blood pressure. It is reliably known that there have been cases where people were completely cured of hypertension after changing their habits and lifestyle.

Why do you need to know blood pressure?

For every 10 mmHg increase, the risk of cardiovascular disease increases by about 30 percent. In people with high blood pressure stroke is seven times more likely to develop, and four times more likely ischemic diseases hearts, two - defeat blood vessels lower extremities.

That is why finding out the cause of symptoms such as dizziness, migraines or general weakness should begin with measuring blood pressure. In many cases, blood pressure needs to be constantly monitored and checked every few hours.

How is blood pressure measured?

In most cases, blood pressure is measured using special device, consisting of the following elements:

pneumatic cuff for compressing the arm;
pressure gauge;
a bulb with a control valve designed for pumping air.

The cuff is placed on the shoulder. During the measurement process, it is necessary to adhere to certain requirements, otherwise the result may be incorrect (underestimated or overestimated), which, in turn, may affect subsequent treatment tactics.

Blood pressure - measurement

The cuff should correspond to the volume of the arm. For people with overweight and children, special cuffs are used.
The environment should be comfortable, the temperature should be room temperature, and you should start after at least a five-minute rest. If it is cold, vascular spasms will occur and blood pressure will rise.
The procedure can be performed only half an hour after eating, drinking coffee or smoking.
Before the procedure, the patient sits down, leans on the back of a chair, relaxes, his legs should not be crossed at this time. The hand should also be relaxed and lie motionless on the table until the end of the procedure (but not on the “weight”).
The height of the table is no less important: it is necessary that the fixed cuff is located at the level of approximately the fourth intercostal space. For every five-centimeter movement of the cuff in relation to the heart, the indicator will decrease (if the limb is elevated) or increase (if it is lowered) by 4 mmHg.
During the procedure, the pressure gauge scale should be located at eye level - this way there will be less chance of making a mistake when reading.
Air is pumped into the cuff just enough to internal pressure it exceeded the estimated systolic blood pressure by at least 30 mmHg. If the pressure in the cuff is too high, pain may occur and, as a result, blood pressure may change. The air should be discharged at a speed of 3-4 mmHg per second, the tones are listened to with a tonometer or stethoscope. It is important that the head of the device does not put too much pressure on the skin - this can also distort the readings.
During the reset, the appearance of the tone (this is called the first phase of Korotkoff sounds) will correspond to the upper pressure. When, during subsequent listening, the tones completely disappear (fifth phase), the resulting value will correspond to the lower pressure.
After a few minutes, the measurement is repeated. An average obtained from several consecutive measurements more accurately reflects the situation than a single procedure.
It is recommended to take the first measurement on both hands at once. Then you can use one hand - the one on which the pressure is higher.

Note! If a person has an abnormal heart rhythm, then measuring blood pressure will be a more difficult procedure. Therefore, it is better for a medical professional to do this.

How to evaluate blood pressure

The higher a person’s blood pressure, the Great chance the occurrence of diseases such as stroke, ischemia, renal failure and so on. To independently assess the pressure indicator, you can use a special classification developed back in 1999.

Table No. 1. Assessment of blood pressure levels. Norm

* — optimal from the point of view of the development of vascular and heart diseases, as well as mortality.

Note! If the upper and lower blood pressure are in different categories, then the one that is higher is selected.

Table No. 2. Assessment of blood pressure levels. Hypertension

Pressure	Upper pressure, mmHg	Lower pressure, mmHg
First degree	From 140 to 159	From 90 to 99
Second degree	From 160 to 179	From 100 to 109
Third degree	Over 180	Over 110
Borderline degree	From 140 to 149	Up to 90
Systolic hypertension	Over 140	Up to 90

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Everything is quite simple. It is one of the main indicators of activity of cardio-vascular system. Let's look at this issue in more detail.

What is blood pressure?

Blood pressure is the process of compression of the walls of capillaries, arteries and veins under the influence of blood circulation.

Types of blood pressure:

upper, or systolic;
lower, or diastolic.

Both of these values should be taken into account when determining your blood pressure level. The very first units of its measurement remain - millimeters of mercury. This is because older machines used mercury to determine blood pressure levels. Therefore, the blood pressure reading looks like in the following way: blood pressure upper (for example, 130) / blood pressure lower (for example, 70) mmHg. Art.

Circumstances that directly affect blood pressure range include:

the level of force of contractions performed by the heart;
the proportion of blood ejected by the heart during each contraction;
resistance of the walls of blood vessels, which is the flow of blood;
the amount of blood circulating in the body;
pressure fluctuations in chest which are caused by the respiratory process.

Blood pressure levels can change throughout the day and as you age. But for most healthy people characterized by a stable blood pressure.

Determination of types of blood pressure

Systolic (upper) blood pressure is a characteristic general condition veins, capillaries, arteries, as well as their tone, which is caused by contraction of the heart muscle. It is responsible for the work of the heart, namely with what force the latter is able to push out blood.

Thus, the level of upper pressure depends on the strength and speed with which heart contractions occur.

It is unreasonable to assert that arterial and cardiac pressure are the same concept, since the aorta also participates in its formation.

The lower one characterizes the activity of blood vessels. In other words, this is the blood pressure level at the moment when the heart is most relaxed.

Lower pressure is formed as a result of contraction peripheral arteries, with the help of which blood enters the organs and tissues of the body. Therefore, the state of blood vessels - their tone and elasticity - is responsible for the level of blood pressure.

How to find out your blood pressure level?

You can find out your blood pressure level using a special device called a “blood pressure tonometer”. This can be done either at the doctor (or nurse) or at home, having first purchased the device at the pharmacy.

Distinguish the following types tonometers:

automatic;
semi-automatic;
mechanical.

A mechanical tonometer consists of a cuff, a pressure gauge or display, an inflation bulb, and a stethoscope. How it works: put the cuff on your arm, place a stethoscope under it (you should hear your pulse), inflate the cuff with air until it stops, and then begin to gradually deflate it by unscrewing the wheel on the bulb. At some point, you will clearly hear pulsating sounds in the headphones of the stethoscope, then they will stop. These two marks are the top and bottom blood pressure.

Consists of a cuff, electronic display and bulb. How it works: put on a cuff, inflate the bulb to the maximum, then release it. The upper and lower values of blood pressure and the number of beats per minute (pulse) appear on the electronic display.

An automatic blood pressure monitor consists of a cuff, an electronic display and a compressor, which performs manipulations to pump and deflate air. How it works: put on the cuff, start the device and wait for the result.

It is generally accepted that a mechanical tonometer gives the most exact result. It is also more affordable. At the same time, automatic and semi-automatic blood pressure monitors remain the most convenient to use. Such models are especially suitable for older people. Moreover, some types have a voice notification function for pressure indicators.

You should measure blood pressure no earlier than thirty minutes after any physical activity (even minor) and an hour after drinking coffee and alcohol. Before the measurement process itself, you need to sit quietly for a couple of minutes and catch your breath.

Blood pressure - normal by age

Each person has an individual one that may not be associated with any diseases.

Blood pressure levels are determined by a number of factors that are of particular importance:

age and gender of the person;
personal characteristics;
life style;
lifestyle features, preferred type of recreation, and so on).

Blood pressure also tends to increase when performing unusual physical activity and emotional stress. And if a person constantly performs physical exercise(for example, an athlete), then the blood pressure level may also change both over time and a long period. For example, when a person is under stress, then his blood pressure can rise to thirty mmHg. Art. from the norm.

However, there are still certain limits for normal blood pressure. And every ten points of deviation from the norm indicates a disruption in the functioning of the body.

Blood pressure - normal by age

Age	Upper level of blood pressure, mm Hg. Art.	Lower blood pressure level, mm Hg. Art.
1 - 10 years
	from 95 to 110
16 - 20 years	from 110 to 120
21 - 40 years old	from 120 to 130
41 - 60 years
61 - 70 years	from 140 to 147
Over 71 years old

You can also calculate your individual blood pressure using the following formulas:

1. For men:

upper blood pressure = 109 + (0.5 * number full years) + (0.1 * weight in kg);
lower blood pressure = 74 + (0.1 * number of completed years) + (0.15 * weight in kg).

2. For women:

upper blood pressure = 102 + (0.7 * number of completed years) + 0.15 * weight in kg);
lower blood pressure = 74 + (0.2 * number of completed years) + (0.1 * weight in kg).

Round the resulting value to a whole number according to the rules of arithmetic. That is, if the result is 120.5, then when rounded it will be 121.

Increased blood pressure

High blood pressure is high level at least one of the indicators (lower or upper). The degree of its overestimation should be judged by taking into account both indicators.

Regardless of whether the lower blood pressure is high or high, it is a disease. And it's called hypertension.

There are three degrees of the disease:

first - SBP 140-160 / DBP 90-100;
second - SBP 161-180 / DBP 101-110;
third - SBP 181 and more / DBP 111 and more.

It is worth talking about hypertension when there is a high level of blood pressure values over a long period.

According to statistics, this figure is overestimated systolic pressure is most often observed in women, and diastolic - in men and the elderly.

Symptoms of high blood pressure may include:

decreased performance;
the appearance of fatigue;
frequent feeling of weakness;
morning pain in the back of the head;
frequent dizziness;
the appearance of nosebleeds;
noise in ears;
decreased visual acuity;
appearing at the end of the day.

Causes of high blood pressure

If lower arterial, then most likely this is one of the symptoms of the disease thyroid gland, kidneys, adrenal glands, which began to produce renin in large quantities. It, in turn, increases the tone of the muscles of blood vessels.

Increased lower blood pressure is fraught with the development of further more serious diseases.

High upper pressure indicates too frequent heart contractions.

A jump in blood pressure can be caused by a number of reasons. This is for example:

narrowing of blood vessels as a result of atherosclerosis;
overweight;
diabetes;
stressful situations;
poor nutrition;
excessive consumption of alcohol, strong coffee and tea;
smoking;
lack of physical activity;
frequent weather changes;
some diseases.

What is low blood pressure?

Low blood pressure is vegetative-vascular dystonia or hypotension.

What happens with hypotension? When the heart contracts, blood enters the vessels. They expand and then gradually narrow. Thus, the vessels help the blood move further along the circulatory system. The pressure is normal. For a number of reasons, vascular tone may decrease. They will remain expanded. There is then not enough resistance for blood movement, which causes the pressure to drop.

Blood pressure level for hypotension: upper - 100 or less, lower - 60 or less.

If the pressure drops sharply, blood supply to the brain is limited. And this is fraught with consequences such as dizziness and fainting.

Symptoms may include:

increased fatigue and lethargy;
the appearance of darkening in the eyes;
frequent shortness of breath;
feeling of coldness in the hands and feet;
increased sensitivity to loud sounds and bright light;
muscle weakness;
motion sickness in transport;
frequent headaches.

What is the cause of low blood pressure?

Poor joint tone and low blood pressure (hypotension) may be present from birth. But more often the culprits low blood pressure become:

Extreme fatigue and stress. Overwork at work and at home, stress and lack of sleep cause a decrease in vascular tone.
It's hot and stuffy. When you sweat, your body leaves a large number of liquids. For the sake of maintaining water balance it pumps water out of the blood that flows through the veins and arteries. Its volume decreases, vascular tone decreases. The pressure drops.
Taking medications. Heart medications, antibiotics, antispasmodics and painkillers can “lower” blood pressure.
Emergence allergic reactions for anything with possible anaphylactic shock.

If you haven't had hypotension before, don't leave it unpleasant symptoms without attention. They can be dangerous “bells” of tuberculosis, stomach ulcers, complications after a concussion and other diseases. See a therapist.

What to do to normalize blood pressure?

These tips will help you feel all cheerful day if you are hypotensive.

Don't rush to get out of bed. When you wake up, do a short warm-up while lying down. Move your arms and legs. Then sit down and stand up slowly. Perform actions without sudden movements. they can cause fainting.
Accept cold and hot shower in the morning for 5 minutes. Alternate the water - one minute warm, one minute cool. This will help you cheer up and is good for blood vessels.
A cup of coffee is good for you! But only natural tart drink will raise the pressure. Drink no more than 1-2 cups a day. If you have heart problems, drink coffee instead green tea. It invigorates no worse than coffee, and does not harm the heart.
Sign up for the pool. Go at least once a week. Swimming improves vascular tone.
Buy ginseng tincture. This natural “energetic energy” gives tone to the body. Dissolve 20 drops of tincture in ¼ glass of water. Drink half an hour before meals.
Eat sweets. As soon as you feel weak, eat ½ teaspoon of honey or a little dark chocolate. Sweets will drive away fatigue and drowsiness.
Drink clean water. Every day, 2 liters of pure and non-carbonated. This will help maintain pressure on normal level. If you have diseased heart and kidneys, drinking regime must be prescribed by a doctor.
Get enough sleep. A rested body will work as it should. Sleep at least 7-8 hours a day.
Get a massage. According to experts oriental medicine, there are special points on the body. By influencing them, you can improve your well-being. The pressure is controlled by the point between the nose and upper lip. Gently massage it with your finger for 2 minutes clockwise. Do this when you feel weak.

First aid for hypotension and hypertension

If you feel dizzy, severe weakness, tinnitus, call an ambulance. While the doctors are on their way, take action:

Unbutton the collar of your clothing. The neck and chest should be free.
Lie down. Lower your head. Place a small pillow under your feet.
Smell the ammonia. If you don't have it, use table vinegar.
Have some tea. Definitely strong and sweet.

If you feel it coming hypertensive crisis, then you also need to call doctors. In general, this disease should always be supported preventive treatment. As first aid measures, you can resort to the following actions:

Organize foot bath With hot water, to which mustard has been previously added. An alternative would be to overlay mustard compresses on the heart area, back of the head and calves.
Lightly wrap your right and then your left arm and leg for half an hour on each side. When the tourniquet is applied, the pulse should be palpable.
Have a drink from chokeberry. It could be wine, compote, juice. Or eat jam from this berry.

To reduce the risk of occurrence and development of hypotension and hypertension, you should adhere to the regimen healthy eating, prevent the appearance excess weight, exclude harmful foods from the list, move more.

Blood pressure should be measured from time to time. If you observe a trend of high or low blood pressure, it is recommended to consult a doctor to determine the causes and prescribe treatment. Prescribed therapy may include methods to normalize blood pressure, such as taking special medications and herbal infusions, dieting, doing a set of exercises, and so on.